title: Assessing low levels of mechanical stress in aortic atherosclerotic lesions from apolipoprotein E-/- mice--brief report.
abstract: OBJECTIVE
  Despite the fact that mechanical stresses are well recognized as key determinants for atherosclerotic plaque rupture, very little is known about stress amplitude and distribution in atherosclerotic lesions, even in the standard apolipoprotein E (apoE)-/- mouse model of atherosclerosis. Our objectives were to combine immunohistology, atomic force microscopy measurements, and finite element computational analysis for the accurate quantification of stress amplitude and distribution in apoE-/- mouse aortic atherosclerotic lesions.
  
  
  RESULTS
  Residual stresses and strains were released by radially cutting aortic arch segments from 7- to 30-week-old pathological apoE-/- (n=25) and healthy control mice (n=20). Immunohistology, atomic force microscopy, and biomechanical modeling taking into account regional residual stresses and strains were performed. Maximum stress values were observed in the normal arterial wall (276±71 kPa), whereas low values (<20 kPa) were observed in all plaque areas. Stress distribution was not correlated to macrophage infiltration.
  
  
  CONCLUSIONS
  Low mechanical stress amplitude was observed in apoE-/- mouse aortic atherosclerotic lesions. This original study provides a basis for further investigations aimed at determining whether low stress levels are responsible for the apparently higher stability of murine aortic atherosclerotic lesions.
authors.affiliation: INSERM U1039, Radiopharmaceutiques Biocliniques, Grenoble, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Broisat
authors.forename: Jakub
authors.initials: J
authors.lastname: Toczek
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mesnier
authors.forename: Philippe
authors.initials: P
authors.lastname: Tracqui
authors.forename: Catherine
authors.initials: C
authors.lastname: Ghezzi
authors.forename: Jacques
authors.initials: J
authors.lastname: Ohayon
authors.forename: Laurent M
authors.initials: LM
authors.lastname: Riou
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology / Q000503:physiopathology*; D001019:Aortic Rupture / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004195:Disease Models, Animal; D020342:Finite Element Analysis; D006439:Hemodynamics; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018625:Microscopy, Atomic Force; D013314:Stress, Mechanical
chemical_list: D001057:Apolipoproteins E